B 67 

£, , KEY 



HELIOGE ASTRA : 



COMBINED REPRESENTATION 



APPARENT and ACTUAL Relative Magnitudes, Posi- 
tions and Movements in Nature, of tlie Sun, Earth, 
Stars, Constellations of the Zodiac and other 
parts of the Heavens, and of the Moon, Tides 
and Visible Planets. 



A Map and Mechanism by which a child, or person of ordinary 
intelligence, will be able to comprehend fully, the fundamental 
principles of the Science of Astronomy, and to exhibit and illustrate 
most of its details. 



Designed for Common and Universal Use, alone, or in 
connection icitli any Books which teach Astronomy. 



BY 



v- 



ANDREW C. LIPPITT, 

NEW LONDON, CONN. 

Sept. 9th, A. D. 1873. 



TELEGRAM PRINT. ESTABLISHMENT, NEW LONDON, CT. 

1874. 



TO THE 

HELIOGE ASTRA: 

OR 

COMBINED REPRESENTATION 



APPARENT ami ACTUAL Relative Magnitudes, Posi- 
tions and Movements in Nature, of the Sun, Earth* 
Stars, Constellations of the Zodiac and. other 
parts of the Heavens, and of the Moon, Tides 
and Visible Planets. 



A Map and Mechanism by which a child, or person of ordinary 
intelligence, -will be able to comprehend fully, the fundamental 
principles of the Science of Astronomy, and to exhibit and illustrate 
most of its details. 



Designed for Common and Universal Use, alone, or iw> 
connection with any Books which teach Astronomy. 






BY 

^]STT3R]E^V^ C. ILIIPDPITT, 

NEW LONDON, CONN. 
Sept, 9th, A. D. 1673. 



3oi>/£- 



TELEGRAM PRINT. ESTABLISHMENT, NEW LONDON, GT. 

1874. 



Entered according to Act of Congress, in the year 1874, by 

ANDREW C. LIPPITT, 
In the Office of the Librarian of Congress, at Washington. 



,iA 



THE HELIOGEASTEA. 



CAPACITY AND CAPABILITIES OF THE 
INSTRUMENT. 

The HELIOGASTRA exhibits, and fully illustrates, 
the actual and apparent relative positions and movements 
of the Sun, Moon, Stars, Earth and other Planets ; marks 
the Zones, or Grand Divisions of Climate on the Earth, 
and presents the reasons therefor. 

It shows the position and Course of the Galaxy, or 
Milky Way, in the heavens ; what Stars, Planets, and 
Constellations of the Zodiac are visible on or near the 
Meridian, or above the Horizon, on any night, at any 
hour of the night, together with the name of each Con- 
stellation and principal star ; and represents the apparent 
and actual position, in nature, of the Sun in the heavens, 
with respect to the Earth in its orbit, on every day in 
the year. ..••'' j 

By it may be shown or calculated sidereal time*' and 
apparent or solar time. '?". 

By it the declination and right ascension, or hi other 
words, the celestial latitude and longitude of the Soifi, 
Moon, Planets, and of every star, may be shown o'r' cal- 
culated, and the hour and minute they each will rise, 
cross the meridian and set throughout the year. 

By it also the method of measuring the distance of the 



lieavenly bodies from the earth is illustrated and made 
clear and satisfactory to the understanding. 

It represents also the sun in its solstitial and equinoctial 
points, and crossing the line, as it is called, together with 
the manner in which the phenomena of Bay and Night, 
Increase and Decrease in the length of days and nights, 
Twilight and Dawn, Heat and Cold, the Seasons, Full 
Moon and its changes, Harvest Moon, Tides, Transits of 
Venus and Mercury, and Eclipses are produced. 



The Map and Mechanism Described and 
Explained. 

So far distant are the heavenly spheres that the eye 
fails to convey to the mind any correct idea of their ac- 
tual positions, and hence the Sun, Moon, Stars, and 
Planetary Orbs, though differing in distance millions and 
billions of miles, all appear to be situated at the same 
distance from us upon the surface of a celestial dome 

In Nature, the Earth seems to occupy a fixed central 
position ; while the Sun and Stars, rising in the East, 
pass over it and set in the West. In point of fact, the 
Sun and Stars are fixed, while the Earth and other Planets 
are revolving on their axes, and moving from West to 
East, in orbits, around the Sun, between it and the Stars. 

The HELIOGE ASTRA preserves in its arrangement 
"both the apparent and actual in Nature, and so combines 
and presents them that they mutually illustrate and ex- 
plain each other. 

The Map is an Astronomical representation or trans- 
cript of the heavens, showing the Celestial Equator, 
Ecliptic, Plane of the Earth's Orbit, Signs of the Zodiac, 
Milky Way, Constellations and principal Stars, with the 



names of each. All the Stare and Constellations are 
placed in their true relative positions, with respect to the 
North Pole and with respect to each other. 

The centre of the Map corresponds to the North Pole 
of the heavens — all lines radiating from that point are lines 
of Celestial longitude. They run South till they meet at 
the South Pole of the heavens. The outer edge of the 
Map corresponds to the Southern horizon. Direction 
from any place on the Map towards the North Pole is di- 
rection North, and direction from the North Pole towards 
any point on the Map is direction South. 

The small circle surrounded by the Names of the 
Months, is in the plane of the Earth's orbit, and has the 
Sun for its centre. 

The HELIOGEASTRA has two Suns. One called the 
Central or Stationary Sun, which is placed upon a pedes- 
tal in the centre of the Map. It corresponds in position 
to the position of the actual Sun in Nature. The other 
Sun, called the movable Sun, is placed upon the end of a 
slotted rod, or arm, and corresponds to the apparent 
position of the Sun in Nature. 

The HELIOGEASTRA has also two Earths. One Earth, 
called the movable Earth, which is placed in a slotted 
arm, or rod, and represents as it is carried around the 
Central Sun, the actual Earth in its orbit. The point 
nearest to the Map is the North Pole, and the point to 
which the handle is attached is the South Pole. Its axis 
is at all times parallel to itself, as the axis of the Earth is 
in Nature. The other Earth is placed at the foot of the 
Map, and is made immovable, as the Earth in Nature 
seems to us to be. If this stationary Earth were a com- 
plete globe, revolving upon its axis, (as we can easily 
imagine it to be.) the rays which pass from the Movable 
1* 



o 

Sun, as it is carried North and South by the Movable 
Earth in its orbit would be cast upon it, at all times, 
precisely as the rays of the Sun in Nature, fall upon the 
Earth in Nature. The illustration would be complete in 
all its parts, and Day and Night, Spring, Summer, Au~ 
tumn and Winter succeed each other, in all places, in their 
regular order. 

The instrument which hangs and revolves upon the 
standard which supports the Central Sun is called the 
Indicator. The interior arm, starting from the North 
Pole of the heavens, is supposed to pass southerly, along 
the arch of the sky, through the Zenith, till it meets the 
horizon at a point within fifty degrees of the South Ce- 
lestial Pole. The exterior arm, starting also from the 
Korth Pole, passes South in like manner, along the con- 
cave of the sky to the Horizon, and thence below, along 
the opposite arch of the sky through the Nadir to the 
South Celestial Pole. 

The curved arms of the Indicator represent the horizon. 
They form a great circle around the Earth, whose poles 
are the Zenith and Nadir. Starting at the horizon, in 
the North, they are supposed to pass along the edge of 
the horizon, East and West, around the heavens. 

The cross-bar is supposed to pass through the centre of 
the Sun, at right angles to the interior and exterior arms 
of the Indicator, cutting the edge of the horizon on the 
East and West. If allowed to assume the position which 
gravity will give it, the interior and exterior arms of the 
Indicator will mark at all times the course of the Meri- 
dian line of the heavens from the North Pole through the 
Zenith and Nadir, to the Southern horizon, and the curv- 
ed arms the actual relative position of the horizon. 

The Central Sun, therefore, in connection with the 



Movable Earth, placed upon the Map among the Fixed 
Stars, and revolving upon its axis as it moves in its orbit, 
represent the Actual in Nature : the stationary revolving 
Earth. Movable Sun, Indicator, and Revolving Map. the 
Apparent , and all, together, the actual and apparent com- 
bined. 

The great Circle, having the North Pole on the Map 
for its centre, is the Celestial Equator, or line which the 
plane of the Earth's Equator would describe if extended 
to the heavens. Distance from that line to points icitluTi 
the circle, is called Declination North ; and distance from 
the line to points without the circle is called Declination 
South. All circles which can be drawn upon the Map 
parallel thereto are parallels of latitude. 

The figures placed along the inner side of the Equato- 
rial line, mark, in degrees, Eight Ascension, beginning at 
the sign Aries. If any point upon the circle be selected, 
all the other points situated upon the same line, in a di- 
rection corresponding to the order of the names of the 
months, will be in a direction due East from it ; and all 
points situated in the opposite direction, will be in a di- 
rection due West of it. Every point, within or without 
the circle, is in a direction either North, South, North 
Easterly, South Easterly, North Westerly or South West- 
erly from the point selected. The same will be true in 
respect to course or direction from points selected, in any 
circle which can be drawn on the Map. having the North 
Pole for its centre. Andromeda is therefore East of 
Pegasus ; the Lynx is East of Auriga ; Bootes is East of 
Ursa Major, and the Lyre East of Hercules. 

Starting from o, at the Equator of the heavens, the 
edge of the interior and exterior arms of the Indicator is 
marked, or spaced off in figures, within and without the 



8 

Equatorial Circle, to mark or measure Declination. Dis- 
tance outside of the Celestial Equator is Declination 
South, and distance inside the Circle is Declination North 
or latitude North. 

The remaining great circle is called the Ecliptic. It 
shows the apparent path of the Sun in the heavens, and 
its apparent position at all times ; for the Sun seems to 
move continually from West to East, through the Signs 
and Constellations of the Zodiac, as the Earth moves in 
its orbit. From the Vernal Equinox to the Summer Sol- 
stice, the line extends within the Equatorial circle, or 
North, as the Sun advances in the heavens ; from that 
point it approaches that circle, in its course, and crosses 
it at the Autumnal Equinox, The Son is then said to 
cross the line. From thence the line proceeds without 
the circle, or South, as the Sun seems to move in the 
heavens to the Winter Solstice, whence it returns again 
and crosses the Equatorial circle at the Vernal Equinox, 
when the Sun is again said to cross the line. 

The figures upon the inner side of the circle mark de- 
grees between the Signs of the Zodiac, and the dots and 
figures upon the outer side, the days of the months : for 
the Sun's apparent position always coincides with the 
point given for the day of the month. 



General Remarks, and Rules to be Observed in 
the Use of the Instrument. 

With respect to the Stationary Earth, the observer is 
supposed to be standing in front, and looking East across 
it, with the North Pole at his left hand and the South 
Pole at his 2 ight ; and with respect to the Map, Zodiac, 



9 

Stars, Earth and other Planets in their orbits, he is sup- 
posed to be standing with his back towards the South 
Pole, and his face towards the North Pole of the heavens. 
It is obvious that as the Earth moves to the right and 
revolves to the right, to a person standing upon the 
Movable Earth, with his face towards the lower or North 
Pole, the right hand will always be East, and the left 
hand West. 

To get a clear and correct conception of the relative 
positions of the Sun, Earth, and Stars in the HELIOGE- ' 
ASTRA, a person must conceive of them as situated 
within, and upon, the interior surface of an immense 
hollow globe ; that a portion of the Southern Pole, or 
end of the globe 50° in length has been removed, and 
that he has entered through the opening into the interior, 
and, while standing upon the Movable Earth, he is ob- 
serving the movements. The Sun is seen to occupy a 
fixed central position, half way between the North and 
South Poles. The exterior Planets and Constellations of 
*he Zodiac occupy their proper places on the surface of 
the Globe upon and near the Celestial Equator, and the 
other Stars and Constellations are spread out upon and 
cover the whole interior surface of the Globe. While the 
Globe with its little firmament of Stars remains fixed and 
immovable, the revolving Earth upon which the observer 
stands, moving in its orbit between the Sun and the 
Stars, brings into view and to the Meridian, in succes- 
sion, each and every Constellation of the Zodiac and of the 
heavens. 

The graduated arms of the Indicator, starting from the 
North Pole as a central point, would be seen passing 
along through the Zenith above and the Nadir below, on 
the surface of the Globe to the opening, marking the 



10 

Meridian line. The curved arms would in like manner 
be seen to pass from about 50" below the North Pole, 
along the interior surface upon opposite sides of the 
Globe, to the edge of the opening, marking the line of 
the horizon, 

Place the Movable Earth upon the name of any month 
in the year ; hold up the HELIOGEASTRA before you 
with the back towards the North Pole of the heavens, in 
such manner that the right arm of the Indicator shall be 
upon the name of the month, and the edge of the left 
arm upon the dot or figure on "the Ecliptic, which stands 
for the day of the month, and the point where the right 
arm crosses the small circle, will then be the true relative 
position of the Earth in its orbit on that daj 7 ; that part 
of the Map which is embraced within the circle, or curved 
arms of the Indicator, will exhibit a transcript of the 
heavens, visible in the Northern hemisphere at the hour 
of six o'clock in the afternoon of that day, and every 
Constellation and important Star visible in the heavens, 
will be found to occupy a corresponding place upon the 
Map, with its name attached. 

Revolve the top of the Heeiogeastea from right to left, 
at the rate of fifteen degrees for every hour, and one de- 
gree for every four minutes, and the Map, with its Stars 
and Constellations rising in the East, passing the Meridi- 
an and setting in the West, will continue to represent in 
like manner, the visible heavens throughout the night. 

The latitude of any observer on the Earth, and his 
Zenith point upon the Sky, Indicator and Map, coincide. 

If a circle be struck upon the Map, passing through 
the point corresponding to the latitude of any observer, 
having the North Pole for its centre, all Stars represented 
on the Map, situated within the circle, will pass the 



11 

Meridian North of such observer's Zenith point in the 
heavens, and all stars situated without the circle, will pass 
the Meridian South of the observer's Zenith point ; and vice 
versa, all the Stars in the firmament which pass the Meri- 
dian any number of degrees, North of the Zenith point of 
an observer, will be found situated upon the Map the 
same number of degrees within the circle, and all Stars 
which pass the Meridian South of the Zenith point of the 
observer, will be found upon the Map the same number 
of degrees outside of the circle. 



THE PLANETS. 

The Exterior Planets, or those situated without the 
orbit of the Earth, are placed among the Stars, where 
they appear to us to be. The interior Planets, or those 
situated within the orbit of the Earth, are placed on 
arbors, at their respective relative distances from the 
Earth and Sun. The exterior Planets may be taken up 
and moved along to correspond with their actual move- 
ments from Constellation to Constellation in the heavens. 

Neptune is a purely telescopic Planet. 

Ueanus is rarely visible, except through a telescope. 

Saturn is visible to the naked eye as a Star of the third 
magnitude, of a pale blueish tint. Provision rs made for 
placing it and preserving a record of its progress from 
Constellation to Constellation around the heavens. 

Jupiter appears to the naked eye as a Star of the first 
magnitude, of a pale yellow color. Ample provision is 
made for preserving a record of its progress among the 
Constellations. 

The Asteroids, situated between Mars and Jupiter, are 
invisible to the naked eye. 



12 

Maes appears like a Star of the second magnitude, and 
of a reddish hue. It can be moved from Constellation to 
Constellation, as the Planet moves. 

Venus is the most conspicuous, and to the naked eye, 
the largest and most brilliant of all the Planets. It is 
always seen in the direction of, and near the Sun, and is 
exceeding bright and beautiful. Its color is silvery 
white. It is placed on an arbor attached to the Sun. 

Meecuey, from its nearness to the Sun, is seldom seen. 
It appears as a star of the third magnitude, and of a pale 
rosy color. It is placed on an arbor next to the Sun. 

The exact position, or right ascension of Mars, or of 
any other of the Planets in the Constellations, may be 
determined, at any time, by referring to the Almanac, 
and multiplying the hours of rising, crossing the Meridi- 
an, or setting, there found, by fifteen, and adding one 
fourth of the minutes to the product. The result will be 
the right ascension of the Planets in degrees on the 
Equator at that time. 

Declination and Right Ascension of the Stars 
and Constellations, and their Times of Grossing 
the Meridian. 

The Stars and Constellations of the Zodiac, and other 
Constellations which cross the Meridian, after six o'clock 
during any given night in the year, will be those situated 
on the Heliogeastea within a distance of 90" on either 
side of the point where the right hand arm of the Indi- 
cator crosses the Celestial Equator, at that hour, on the 
day named. And, as the Earth is constantly revolving 
on its axis from West to East, while the Stars remain 
stationary, the Constellations will rise, appear on the 



13 

Meridian, and set in succession ; those placed at a dis- 
tance of 45° West of the point, will be over-head at nine 
o'clock in the evening, those situated immediately above 
the point named, at midnight, and those situated at a 
distance of 45° East of the point, will be over-head at 
three o'clock in the morning. 

Place the graduated edge of the interior arm of the 
Indicator at the centre of any Star, and the number of 
degrees represented on the Equatorial line, at the place 
where it is crossed, shows its right ascension ; the dis- 
tance in degrees at which it is situated outside or inside 
of that line, shows its declination, or latitude North or 
South. The place where it crosses the small circle, shows 
the month ; and the place where the exterior arm crosses 
the Ecliptic shows the day of the month on which the 
Star will cross the Meridian. And, if you divide the 
number jf degrees shown at the point where the interior 
arm crosses the Equatorial line, by fifteen for the hours 
and multiply the remainder, if there be any, by four, for 
the minutes, the result will show what hour and minute 
of the twenty-four, Sidereal time, the Star will cross the 
Meridian. 



How Heat and Cold, Spring, Summer, Autumn 
and Winter are produced. Winter and Summer 
Solstice. 

The Sun is said to be vertical, over any point on the 
Earth, when a line, drawn from the centre of the Sun to 
the centre of the Earth, would pass through it. 

The various parts of the Earth are warmest when the 
Sun is nearest vertical over them, and coldest when the 
rays of the Sun fall most obliquely upon them. 
2 



14 

It is therefore the change in direction in which the 
rays of the Sun. fall upon the Earth, and not a change of 
the distance of the Sun from the Earth, (for it is nearer 
by about three millions of miles in January than in July,) 
which produces the changes of heat and cold, and, con- 
sequently, Spring, Summer, Autumn, and Winter, on the 
Earth. These changes in the direction of the rays of the 
Sun, are caused by the change in the relative positions of 
the poles of the Earth with respect to the Sun as it moves 
in its orbit. They will be made strikingly apparent to 
the observer by placing the Earth in the Equinoctial, and 
then in the Solsticial points, and noting the change in the 
direction of the rays, from the movable Sun, as they fall 
upon the stationary Earth. For six months in the year 
the South Pole is illuminated and the North Pole in dark- 
ness, and for the remaining six months the North Pole is 
illuminated and the South Pole in darkness. A person 
standing at the Equator of the stationary Earth, on the 
20th day of March and 23d day of September, would see 
the Sun directly over his head ; from March to June, far- 
ther and farther to the Northward, and from September 
to December, farther and farther to the Southward of 
him, on each succeeding day. Precisely the same 
changes, in the direction of the Sun's rays, would be ob- 
served by a person standing on the Equator of the mova- 
ble Earth in its orbit. It is evident, therefore, that the 
apparent changes, in the position of the Sun, in Nature, 
are not owing to any actual change, as it seems to us to 
be, but wholly to a change of the direction in which its 
rays come to us, by reason of the change of the position 
of the Earth, while its axis remains unchanged. 

As the Earth is moved around the central Sun of the 
Heliogeastra, the position of the movable Sun, with 



15 

respect to the stationary Earth, shows the true apparent 
position of the Sun in the heavens, in Nature, at all 
times and places, and not only that, but the direction in 
which the rays from the movable Sun fall upon the sta- 
tionary Earth, exhibits to the eye a record of the manner 
in which the rays of the Sun, in Nature, are falling 
upon the Earth in Nature, the changing seasons, as they 
actually exist, in all parts of the Earth, on every day in 
the year. 

Spring actually commences, in the Northern Hemis- 
phere, when the Sun crosses the Equinoctial line, on the 
20th day of March, and in the Southern Hemisphere,' 
w T hen the Sun crosses the Equinoctial line, on the 23d 
day of September. 

For a number of days, prior and subsequent to the 23d 
day of December and the 21st day of June, in each year, 
w T hen the Earth reaches those po'nts in its orbit*, the ap- 
parent change of the position of the Sun is so very slight, 
as is shown by the movable Sun in the Hemcgeastra, that 
it is said to stand still. For that reason those points are 
called the Winter and Summer Solstice. They mark the 
time w r hen Winter and Summer respectively begin. 



ZONES AND CLIMATES. 

It will be Reen, as the Earth is moved around the cen- 
tral Sun, that the movable Sun remains vertical, or 
nearly vertical, over all parts of the stationary Earth 
stuated between the lines marked as the Tropic of Cancer 
and Tropic of Capricorn; that it is never vertical North 
or South of those points ; hence, that part of the Earth, 
because of the extreme heat which prevails, is called the 



16 

Torrid Zone, and the climate Tropical, because it lies 
between the Tropic lines. 

Within the Arctic and Antarctic circles, the rays of the 
Sun fall very obliquely upon the Earth. At the poles, 
for six months in the year, and, as far down as the Arctic 
and Antarctic circles, on the 23d day of December and 
21st day of June, alternately, they do not touch it at all. 
For this reason, the climate is intensely cold, and the 
regions themselves are called Frigid Zones. 

North and South of the Equator, between the Polar 
circles and the Tropic lines, as the rays of the Sun are 
never vertical, as in the Torrid Zone, and never fall so 
obliquely as within the Polar Circles, the extremes of 
heat and cold, peculiar to those regions, never prevail, 
and the climate is called Temperate, and the regions 
themselves Temperate Zones. 



Day and Night, Twilight and Dawn, and Times 
of Rising and Setting of the Stars. 

The rising and setting of the Sun divides the hours 
into day and night. The phenomenon, called the rising 
and setting of the Sun and Stars, is caused by the revo- 
lution of the Earth on its axis. At the same instant of 
time, it is noon to the people residing on the side of the 
Earth next to the Sun, Midnight to those living at the 
opposite point, Sunrise to those coming around to the 
poiut where they can just see the rays of the Sun, and 
Sundown to those just passing out of the rays of the Sun 
into the shades of evening, or shadow of the Earth. 

The Earth moves in an Elliptical Orbit, and is about 
three millions of miles nearer the Sun on the first day of 



17 

January, than it is on the third day of July. Its velocity 
is accelerated or retarded by the attraction of the Sun as 
it advances towards or recedes from the point in its orbit 
nearest the Sun. 

\vhen the oun is on the Equator, or crossing the Equi- 
noctial line, as it is called, it rises and sets at six o'clock, 
and the days and nights are, consequently, of equal 
length, in all parts of the globe. 

To the people in the Northern hemisphere, the South- 
ern horizon, with respect to the Sun, from the 20th day 
of March to the 23d day of September seems to be de- 
pressed, causing the Sun to appear earlier, and remain 
longer, than six o'clock, above the horizon ; and from the 
23d day of September to the 20th day of March to rise 
again, causing the Sun to appear later above, and to sink 
earlier beneath the horizon than six o'clock. 

This is owing entirely, as before explained, to the 
change of the relative position of the axis of the Earth, 
with respect to the Sun, as it moves in its orbit. 

Place the Moon at its full, or change, when the Earth- 
is at one of the Equinoxes, and then move the Earth- 
around its orbit, revolving it as it moves, while the 
Moon is held in the same position, and the plane which 
the Moon des3ribes as it moves, with respect to the Sun, 
six months below and six months above it, will beauti- 
fully illustrate the apparent rolling, or dipping and rising 
of the line of the horizon, at different periods of the year. 
The Sun is longest above the horizon, and the days 
longest at any place, when the Sun apparently rises 
highest above the horizon, or towards the Meridian, at 
noon. The days and nights increase or diminish in 
length, relatively, North or South of the Equator, as the 
vertical rays of the Sun advance towards, or recede from 
2* 



18 

the Tropic lines. It is this change in the rate of the 
Earth's motion, in connection with the relative change 
of its axis, with respect to the Sun, which causes the 
difference in the length of days and nights on the Earth. 

Bring the curved edge of the right, or Eastern, arm of 
the Indicator, to the centre of a rising Star, or the curv- 
ed edge of the left, or Western, arm of the Indicator, to 
the centre of a setting Star ; ascertain, in each case, the 
number of degrees and parts of a degree there are on the 
Ecliptic, between the point for the day named, and the 
point where the curved edge of the Indicator crosses the 
Ecliptic ; divide the number of degrees and parts of a 
degree thus found, by fifteen for the hours, and multiply 
the remainder, if there be any, by four, for the minutes ; 
add the product to six hours, if after, and subtract it 
from six hours, if before six o'clock, and the result will be 
the time the Star will rise or set, as the case may be. 

Twilight begins, morning and evening, at any place 
when, and continues as long as, the rays of the Sun, 
from the West or East, passing across the Earth, strike 
the particles of matter in our atmosphere, at such angles 
as to throw their light to the Earth. 

Twilight begins earliest, and lasts longest, in those 
parts of the Earth, where the rays of the Sun fall most 
obliquely. 



Declination of the Sun. Sidereal Time, Solar 
Time, and Mean Solar or Clock Time. 

The declination of the Sun, is its distance, in degrees, 
inside or outside the circle of the Celestial Equator. 
Sidereal time is time measured from one transit to ano- 
ther of a Star across the Meridian. 



19 

Solar time is time measured from the time the Sun. 
crosses the Meridian of any particular place, till it shall 
cross it again. Add three minutes and fifty-six (3 m. 56 
sec.) seconds to sidereal time, and the pre duct will be 
solar time. Mean solar, or clock time, is the average of 
all the solar days. By it the days are made to consist of 
twenty- four hours each. The Sun is sometimes faster 
and sometimes slower than the clock. On the 15th of 
April, 15th of June, 1st of September, and 23d of Decem- 
ber, they agree. 

The time when the Sun, or any Planet or Star, will 
rise, cross the Meridian or set, having been ascertained, 
from an almanac calculated for any particular Meridian, 
all that is necessary to do, to accommodate it to your 
place of observation, is to add or subtract the difference 
in longitude, between that place and your place of obser- 
vation, one hour for every fifteen degrees, and four 
minute s for each additional degree of longitude. 



The Moon and its Changes. Harvest Moon, 

The Moon revolves around the Earth in 29^ of our 
days, and revolves but once on its axis during its 
revolution around the Earth. The effect is the same, 
with respect to the Earth, as it would be, if it were 
placed upon the end of a spindle, as it is exhibited in the 
Heliogeastra. The same side is always turned towards, 
the Earth. 

It is New Moon when it comes into a position nearest 
the Sun ; in Quadrature, or is said to quarter, when, with 
the Earth and Sun, it forms a right angle ; and Full 
Moon, when it reaches a point, on the side of the Earth 



20 

farthest from the Sun. New Moon appears smallest, and 
Full Moon largest, whea the Earth, Moon and Sun are 
nearest to being on the same line. 

It rises farthest South, when the Sun seems to rise 
farthest North, and farthest North when the Sun seems 
to rise furthest South. This phenomenon of Nature and 
the reason for it, will be obvious to any one, who will 
carefully inspect the working of the Heliogeastea. 

On the 20th day of September, the Horizon and Eclip- 
tic are nearly parallel. If, at that time the Moon shall 
be at its full, and rise at six o'clock on the Ecliptic, it 
will, by reason of its position, rise later by less than 
thirty minates, on each successive night, for several 
nights. The days for labor in the gathering in of the 
harvest, are thereby prolonged, and the Moon is called 
the Harvest Moon. 



TIDES. 

Tides on the Earth, are the effect of the Moon and 
Sun's attraction, drawing the waters and atmosphere of 
the Earth towards themselves. The attraction is greatest, 
and the highest, or Spring tides formed, when the Sun, 
Moon and Earth are all in the same line and act together; 
and least, and Neap tides formed, when they are so situ- 
ated as to act at right angles, and thus in part neutralize 
the effects of each other. 

Tides are formed, at the same time, on opposite sides 
of the Earth, under and opposite the Moon, and move 
around from East to West, in manner shown in the 
Heliogeastea, as the Earth revolves. "When it is high 
tide at any two points, on opposite sides of the globe, it 
is low water, on opposite sides of the Eaitb, just half way 
between them. 



21 



TRANSITS AND ECLIPSES. 

An Eclipse of the Sun occurs when the Moon in its- 
orbit, passes between the Earth and Sun in such manner 
as to intercept a portion of its rays. It is visible, only, 
to those people living on the line of intercepted rays. It 
is partial to those within the penumbra, and total to those 
within the umbra. 

An Eclipse of the Moon takes place when the Earth 
passes between it and the Sun, so as to intercept the rays 
of the Sun on their way to the Moon. 

Eclipses of the Sun always occur at New Moon, and 
Eclipses of the Moon always at Full Moon. 

As the Moon revolves around the Earth in a different 
plane from that of the Earth around the Sun, Eclipses 
cannot occur except when the Moon is near its Nodes, or 
plane of the Earth's orbit ; that is to say, within 17 ? at 
the time of her change, or within 12 Q at the time of her 
full. 

There can never be less than two Eclipses in a year. 
There may be seven in all : five Solar and two Lunar. 
The most usual number is four. When there are but 
two, both will be of the Sun. 

A Transit is said to occur when a heavenly body crosses, 
at the same time, the disk of the Sun and the Meridian 
of any place. A Planet will pass, or seem to pass over 
the disk of the Sun, when it passes on a line between our 
Planet and the Sun. This can never happen, except 
when the Planet is near the Ecliptic, or its Nodes. The 
Transits of Yenus occur only in December and June, and 
of Mercury only in May and November. 



22 

Methods of Measuring the 
Distances of the Heavenly Bodies from the Earth. 

There is a rule, in Mathematics, by which, if one of 
three sides of a triangle, A. B., and C 

the angles A. B. C. and B. A. C, which 
the two adjacent sides make with it, 
are known, the length of the remain- 
ing sides, or of a line drawn at right 
angles from the side whose length is 
given, to the point of the remaining 
angle (C. D.), can be readily deter- 
mined. 




a r> b 

This rule is familiar to Surveyors, and is constantly 
applied by them, in making survey of lands, when they 
wish to ascertain the distance across a lake or river, or 
to any object which is inaccessible. 

Place the movable Sun, in the Heliogeastba, on the 
line of the Equinoxes, and the lines or rays passing from 
it to the poles of the stationary Earth, in connection with 
the axis of the stationary Earth, will form such a triangle. 

The length of the axis of the stationary Earth, in the 
Heeiogeastka, and the length cf the axis of the Earth, 
in Nature, both being known, if the argles are also 
known, which the lines, drawn from the poles of the 
stationary Earth to the movable San, make with the axis 
of the s ationary Earth, in the one case, and the angles 
which the lines of sight, from the poles of the Earth, to 
the Sun, in Nature, make, with the axis of the Earth, in 
Nature, in the other, it is <_bvious, that, by applying the 
rule with re- pect to triangles, above referred to, the dis- 
tance from the stationary Earth to the movable Sun, in 



23 

the Heeiogeastra, or, from the Earth, in Nature, to the 
Sun, in Nature, could be easily ascertained. 

The same results would be reached if any two points 
on the Earth, and the distance between those points, as, 
for instance, between Cape Horn and the City of Boston, 
or Greenwich and the Cape of Good Hope, were taken 
as a basis for this calculation. 

Should such a test be applied to the Sun and Moon, it 
would be found that the Sun is about 95,000,000, and 
the Moon about 240,000 miles from the Earth. 

Since, therefore, such is the distance of the Sun from 
the Earth, if there are any persons who still hesitate to 
believe the statements of Astronomers, deeming the con- 
clusions of Science incredible, that the Earth revolves 
upon its axis, at the rate of 1000 miles per hour, thereby 
producing the changes of day and night every twenty-four 
hours, and that it moves sufficiently rapid through space 
to -perform the circuit of its journey, aiound the Sun, a 
distance of about 570,000,000 of miles, in a period of one 
year, thereby producing the changes of Spring, Summer, 
Autumn and Winter, they must take the other alternative 
and believe that the Sun, a body 1,400,000 times larger 
than our Earth, large enough to appear of the size it does, 
at a distance from us of 95,000,000 of miles, revolves 
around the Earth, performing the same journey, of about 
570,000,000 of miles, in a period of twenty-four hours, 
and thereby produces the changes of day and night — and 
not only so, but that it swings, from its extreme point of 
rising South in December, to the extreme point of rising 
North in July, over a space of 47° of the Eastern horizon* 
about 75,000,000 of miles, and back again to the same 
point in December, thereby producing the change of 
Seasons. 



24 

The conclusions of science are wonderful, but the 
other alternative surpasses belief. 

By inspection of the Heliogeastba, we shall see that 
the Earth's position, in January and July, is on opposite 
sides of the Sun. The distance across its orbit is twice 
the distance from the Earth to the Sun, or about 
190,000,000 of miles It is obvious, therefore, that if 
lines were drawn from the termini of a line across the 
Earth's orbit, to any Star on the Map, they would form 
with that line another triangle. 

Now, if a person on the first day of January, and again 
on the third day of July, by means of an instrument, 
used for the purpose of measuring angles, should look at 
a distant Star, and thus ascertain the angles which these 
two lines of sight make with the line across the orbit of 
the Earth, we should expect that, by applying the rule 
referred to, he would be able to measure the distance 
of the Star from the Earth. Such would be the fact, if 
the Star were not more distant than (20,000,000,000) 
twenty billions of miles. But when we apply the test to 
a fixed Star, the distance across the orbit of the Earth is 
so short, in comparison with the distance to the Star, 
that the lines of sight form no angle with it, and approach 
so near to parallel lines, that the difference cannot be 
appreciated by any instrument which has yet been con- 
structed. Hence, the actual distance to the Stars cannot 
be measured. It is known, however, that the nearest of 
them is distant more than twenty billions of miles, but 
how far beyond, in the far off space, it is impossible for 
xnan, with his present knowledge of Astronomy, to tell. 



25 



THE SUN. 

In the Heliogeastra the Sun is represented as immov- 
able, in a central position. Such, however, is not its 
actual condition, in Nature. It is revolving around some 
distant central orb, as the Earth moves around it. Pro- 
fessor Madler, a distinguished Astronomer, of Dorpat, in 
Russia, has announced, that Alcyone, one of the Pleiades, 
or Seven Stars, as they are called, is that Central Orb. 
It is so far distant as to appear to us but a mere speck of 
light in the firmament Astronomers also tell as that the 
Sun is a body about 1,400,000 times larger than our 
Earth ; that the Planets were once a part of its substance, 
and have been thrown off from its surface, at different 
periods of its history ; that it is now moving through 
space, in the direction of the Constellation Hercules, and 
will continue to move off in space, in the same general 
direction, at the rate of about 38,000 miles the hour, for 
a period of 9,100,000 years, its period being 18,200,000 
of our years; and that, so immense is the circle of its 
orbit, that it has passed over but about 1-3000 part of its 
orbit since Man was placed upon the Earth Has it ever 
been around its Central Orb ? How many times ? Has 
it passed its perihelion as many times as there are Planets 
in our System, casting off one at every revolution ? How 
immense must be the circuit of the Sun ! How vast the 
actual magnitude of its Central * Orb, whether it be 
Alcyone or any other fixed Star in the heavens, visible or 
invisible to the naked eye, since it is certain that it is 
large enough to curb the fiery Sun in its course, with all 
its retinue of Planets, and determine its orbit, at such 
3 



26 

vast distance, by the mere power of attraction ! Science 
fails to compass, the imagination is lost in the contem- 
plation of Magnitude, Time, Distance and Space, so 
immense, and the problems must be left for future minds 
to solve. 



LIBRARY OF CONGRESS 



. Jill 

003 538 811 4 #i 



